Revert r11503 as it breaks device adapters.
Revert r11503 as it breaks device adapters.

The added convenience function breaks legitimate use of the existing
CreateProperty() with pAct = 0.

git-svn-id: 03a8048b5ee8463be5048a3801110fb50f378627@11506 d0ab736e-dc22-4aeb-8dc9-08def0aa14fd

kmdouglass/Micro-Manager,kmdouglass/Micro-Manager